src/server/biomes.c

   1 #include <math.h>
   2 #include "server/biomes.h"
   3 #include "server/server_terrain.h"
   4 #include "server/terrain_gen.h"
   5
   6 Biome get_biome(v2s32 pos, f64 *factor)
   7 {
   8         for (Biome i = 0; i < COUNT_BIOME; i++) {
   9                 BiomeDef *def = &biomes[i];
  10                 f64 f = def->probability == 1.0 ? 1.0
  11                         : (smooth2d(U32(pos.x) / def->threshold, U32(pos.y) / def->threshold, 0, seed + def->offset) * 0.5 - 0.5 + def->probability) / def->probability;
  12
  13                 if (f > 0.0) {
  14                         if (factor)
  15                                 *factor = f;
  16                         return i;
  17                 }
  18         }
  19
  20         return COUNT_BIOME;
  21 }
  22
  23 // mountain biome
  24
  25 static s32 height_mountain(BiomeArgsHeight *args)
  26 {
  27         return pow((args->height + 96) * pow(((smooth2d(U32(args->pos.x) / 48.0, U32(args->pos.y) / 48.0, 0, seed + SO_MOUNTAIN_HEIGHT) + 1.0) * 256.0 + 128.0), args->factor), 1.0 / (args->factor + 1.0)) - 96;
  28 }
  29
  30 static NodeType generate_mountain(BiomeArgsGenerate *args)
  31 {
  32         return args->diff <= 0 ? NODE_STONE : NODE_AIR;
  33 }
  34
  35 // ocean biome
  36
  37 typedef enum {
  38         OCEAN_EDGE,
  39         OCEAN_BEACH,
  40         OCEAN_MAIN,
  41         OCEAN_DEEP,
  42         COUNT_OCEAN
  43 } OceanLevel;
  44
  45 static f64 ocean_level_start[COUNT_OCEAN] = {
  46         0.0,
  47         0.1,
  48         0.2,
  49         0.5,
  50 };
  51
  52 typedef struct {
  53         bool has_vulcano;
  54         v2s32 vulcano_pos;
  55 } OceanChunkData;
  56
  57 typedef struct {
  58         bool vulcano;
  59         bool vulcano_crater;
  60         s32 vulcano_height;
  61         s32 vulcano_crater_top;
  62         NodeType vulcano_stone;
  63 } OceanRowData;
  64
  65 static const f64 vulcano_radius = 256.0;
  66 static const f64 vulcano_chunk_offset = vulcano_radius * 2.0 / CHUNK_SIZE;
  67
  68 static OceanLevel get_ocean_level(f64 factor)
  69 {
  70         if (factor >= ocean_level_start[OCEAN_DEEP])
  71                 return OCEAN_DEEP;
  72         else if (factor >= ocean_level_start[OCEAN_MAIN])
  73                 return OCEAN_MAIN;
  74         else if (factor >= ocean_level_start[OCEAN_BEACH])
  75                 return OCEAN_BEACH;
  76
  77         return OCEAN_EDGE;
  78 }
  79
  80 static f64 get_ocean_level_factor(f64 factor, OceanLevel level)
  81 {
  82         f64 start, end;
  83         start = ocean_level_start[level];
  84         end = ++level == COUNT_OCEAN ? 1.0 : ocean_level_start[level];
  85
  86         return (factor - start) / (end - start);
  87 }
  88
  89 static bool is_vulcano(v2s32 pos)
  90 {
  91         f64 factor;
  92
  93         return noise2d(pos.x, pos.y, 0, seed + SO_VULCANO) > 0.0
  94                 && get_biome((v2s32) {pos.x * CHUNK_SIZE, pos.y * CHUNK_SIZE}, &factor) == BIOME_OCEAN
  95                 && get_ocean_level(factor) == OCEAN_DEEP;
  96 }
  97
  98 static bool find_near_vulcano(v2s32 pos, v2s32 *result)
  99 {
 100         f64 x = pos.x / vulcano_chunk_offset;
 101         f64 z = pos.y / vulcano_chunk_offset;
 102
 103         s32 lx, lz;
 104         lx = floor(x);
 105         lz = floor(z);
 106
 107         s32 hx, hz;
 108         hx = ceil(x);
 109         hz = ceil(z);
 110
 111         for (s32 ix = lx; ix <= hx; ix++) {
 112                 for (s32 iz = lz; iz <= hz; iz++) {
 113                         v2s32 vulcano_pos = {ix * 32, iz * 32};
 114
 115                         if (is_vulcano(vulcano_pos)) {
 116                                 *result = vulcano_pos;
 117                                 return true;
 118                         }
 119                 }
 120         }
 121
 122         return false;
 123 }
 124
 125 static f64 distance(v2s32 a, v2s32 b)
 126 {
 127         return sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2));
 128 }
 129
 130 static s32 calculate_ocean_floor(f64 factor, s32 height)
 131 {
 132         switch (get_ocean_level(factor)) {
 133                 case OCEAN_EDGE:
 134                         return f64_mix(height + 1, 0, pow(get_ocean_level_factor(factor, OCEAN_EDGE), 0.8));
 135
 136                 case OCEAN_BEACH:
 137                         return 0;
 138
 139                 case OCEAN_MAIN:
 140                         return f64_mix(0, -10, pow(get_ocean_level_factor(factor, OCEAN_MAIN), 0.5));
 141
 142                 case OCEAN_DEEP:
 143                         return f64_mix(-10, -50, pow(get_ocean_level_factor(factor, OCEAN_DEEP), 0.5));
 144
 145                 default:
 146                         break;
 147         }
 148
 149         return height;
 150 }
 151
 152 static void chunk_ocean(BiomeArgsChunk *args)
 153 {
 154         OceanChunkData *chunk_data = args->chunk_data;
 155         v2s32 vulcano_pos;
 156
 157         if ((chunk_data->has_vulcano = find_near_vulcano((v2s32) {args->chunk->pos.x, args->chunk->pos.z}, &vulcano_pos)))
 158                 chunk_data->vulcano_pos = (v2s32) {vulcano_pos.x * CHUNK_SIZE, vulcano_pos.y * CHUNK_SIZE};
 159 }
 160
 161 static void row_ocean(BiomeArgsRow *args)
 162 {
 163         OceanChunkData *chunk_data = args->chunk_data;
 164         OceanRowData *row_data = args->row_data;
 165
 166         row_data->vulcano = false;
 167
 168         if (chunk_data->has_vulcano) {
 169                 f64 dist = distance(args->pos, chunk_data->vulcano_pos);
 170
 171                 if (dist < vulcano_radius) {
 172                         f64 crater_factor = pow(asin(1.0 - dist / vulcano_radius), 2.0);
 173                         f64 vulcano_height = (pnoise2d(U32(args->pos.x) / 100.0, U32(args->pos.y) / 100.0, 0.2, 2, seed + SO_VULCANO_HEIGHT) * 0.5 + 0.5) * 128.0 * crater_factor + 1.0 - 30.0;
 174                         bool is_crater = vulcano_height > 0;
 175
 176                         if (!is_crater)
 177                                 vulcano_height = f64_min(vulcano_height + 5.0, 0.0);
 178
 179                         if (vulcano_height < 0)
 180                                 vulcano_height *= 2.0;
 181
 182                         row_data->vulcano = true;
 183                         row_data->vulcano_crater = is_crater;
 184                         row_data->vulcano_height = floor(vulcano_height + 0.5);
 185                         row_data->vulcano_crater_top = 50 + floor((pnoise2d(U32(args->pos.x) / 3.0, U32(args->pos.y) / 3.0, 0.0, 1, seed + SO_VULCANO_CRATER_TOP) * 0.5 + 0.5) * 3.0 + 0.5);
 186                         row_data->vulcano_stone = is_crater
 187                                 ? ((pnoise2d(U32(args->pos.x) / 16.0, U32(args->pos.y) / 16.0, 0.85, 3, seed + SO_VULCANO_STONE) * 0.5 + 0.5) * crater_factor > 0.4
 188                                         ? NODE_VULCANO_STONE
 189                                         : NODE_STONE)
 190                                 : NODE_SAND;
 191                 }
 192         }
 193 }
 194
 195 static s32 height_ocean(BiomeArgsHeight *args)
 196 {
 197         OceanRowData *row_data = args->row_data;
 198
 199         s32 ocean_floor = calculate_ocean_floor(args->factor, args->height);
 200         return row_data->vulcano ? f64_max(ocean_floor, row_data->vulcano_height) : ocean_floor;
 201 }
 202
 203 NodeType ocean_get_node_at(v3s32 pos, s32 diff, void *_row_data)
 204 {
 205         OceanRowData *row_data = _row_data;
 206
 207         if (row_data->vulcano && row_data->vulcano_crater) {
 208                 if (diff <= -5)
 209                         return pos.y <= 45 ? NODE_LAVA : NODE_AIR;
 210                 else if (diff <= 0)
 211                         return pos.y <= row_data->vulcano_crater_top ? row_data->vulcano_stone : NODE_AIR;
 212                 else
 213                         return NODE_AIR;
 214         } else {
 215                 if (diff <= -5)
 216                         return NODE_STONE;
 217                 else if (diff <= 0)
 218                         return NODE_SAND;
 219                 else if (pos.y <= 0)
 220                         return NODE_WATER;
 221         }
 222
 223         return NODE_AIR;
 224 }
 225
 226 static NodeType generate_ocean(BiomeArgsGenerate *args)
 227 {
 228         return ocean_get_node_at(args->pos, args->diff, args->row_data);
 229 }
 230
 231 // hills biome
 232
 233 static bool boulder_touching_ground(v3s32 pos, s32 diff)
 234 {
 235         for (s32 dir = diff > 0 ? -1 : +1; dir > 0 ? diff <= 0 : diff >= 0; pos.y += dir, diff += dir) {
 236                 if (smooth3d(U32(pos.x) / 12.0, U32(pos.y) / 6.0, U32(pos.z) / 12.0, 0, seed + SO_BOULDER) < 0.8)
 237                         return false;
 238         }
 239
 240         return true;
 241 }
 242
 243 static s32 height_hills(BiomeArgsHeight *args)
 244 {
 245         return args->height;
 246 }
 247
 248 static NodeType generate_hills(BiomeArgsGenerate *args)
 249 {
 250         if (boulder_touching_ground(args->pos, args->diff))
 251                 return NODE_STONE;
 252
 253         if (args->diff <= -5)
 254                 return NODE_STONE;
 255         else if (args->diff <= -1)
 256                 return NODE_DIRT;
 257         else if (args->diff <= 0)
 258                 return NODE_GRASS;
 259
 260         return NODE_AIR;
 261 }
 262
 263 BiomeDef biomes[COUNT_BIOME] = {
 264         {
 265                 .probability = 0.2,
 266                 .offset = SO_MOUNTAIN,
 267                 .threshold = 1024.0,
 268                 .snow = true,
 269                 .height = &height_mountain,
 270                 .generate = &generate_mountain,
 271                 .chunk_data_size = 0,
 272                 .chunk = NULL,
 273                 .row_data_size = 0,
 274                 .row = NULL,
 275         },
 276         {
 277                 .probability = 0.2,
 278                 .offset = SO_OCEAN,
 279                 .threshold = 2048.0,
 280                 .snow = false,
 281                 .height = &height_ocean,
 282                 .generate = &generate_ocean,
 283                 .chunk_data_size = sizeof(OceanChunkData),
 284                 .chunk = &chunk_ocean,
 285                 .row_data_size = sizeof(OceanRowData),
 286                 .row = &row_ocean,
 287         },
 288         {
 289                 .probability = 1.0,
 290                 .offset = SO_NONE,
 291                 .threshold = 0.0,
 292                 .snow = true,
 293                 .height = &height_hills,
 294                 .generate = &generate_hills,
 295                 .chunk_data_size = 0,
 296                 .chunk = NULL,
 297                 .row_data_size = 0,
 298                 .row = NULL,
 299         },
 300 };